Tufting machine yarn feed pattern control

ABSTRACT

A tufting machine has a yarn feed pattern assembly including a housing having a mounting plate for mounting a multiplicity of yarn feed rollers from the exterior of said mounting plate and a multiplicity of servo motors connected to said mounting plate on the interior of said housing. Each servo motor is connected to a respective feed roller. A multiplicity of tubes extend within said housing, half the tubes directing yarn from a source to respective rollers and half of the tubes directing yarn from the rollers to respective needles. The guide tubes direct yarn from the interior of said housing through said mounting plate where the yarn is trained about a respective roller and directed back into the yarn guide leading toward the needles of said tufting machine.

This invention relates to tufting machines and more particularly to ayarn feed pattern control for a tufting machine having a separate feedmotor for each individual yarn end fed to the tufting machine forvarying the pile height of each tuft selectively, thereby permitting afull repeat across the full width of the tufting machine.

It is well known in the carpet tufting art to utilize a yarn feed rollerattachment for producing variations in pile height of loop pileproducts, and for producing cut and loop products wherein any particularneedle may produce either a loop pile tuft or a cut pile tuft. The yarnfeed rollers act either to feed the full amount of yarn to adequatelyaccommodate the yarn requirements of the particular needle or to feedless than that adequate amount of yarn so as to backdraw or backrob yarnfrom the previous stitch. The backrobbing features are adequatelydescribed in the prior art, for example, U.S. Pat. No. 2,862,465 inregard to loop pile and U.S. Pat. No. 3,084,645 in regard to cut andloop products.

As described in U.S. Pat. No. 5,182,997, each needle in the tuftingmachine may be controlled individually to either produce a high loop ora low loop by feeding yarn to each of the respective needles at a firstor a second speed, the first and second speeds being different. Thegreater quantity of yarn fed at the highest speed provides an adequateamount of yarn for the needle while the slower speed supplies a lesseramount so as to backrob from the prior loop. The assembly there shown isknown as a single end control yarn feed roller assembly or a full repeatscroll and is a two pile height feed roller assembly. There are otherfeed roller assemblies of this type that may permit a third level to beformed by including an additional drive roll pair for driving the feedroll at a third speed intermediate the first and second speeds.

Recently, with the improvements made in the art of servo motors whereinsuch motors have been made smaller and quick acting, it is now possibleto drive a single yarn end by a respective servo motor to eachindividual needle. This provides the ability to feed each yam at amultitude of speeds to each needle so that a substantial number of pileheights may be produced by each individual needle. This gives the carpetdesigner a substantially greater arsenal of design capabilities thanheretofore possible. For example, certain needles may be threaded withdifferent color yarns and a particular color yam may be hidden it thecarpet at a first location and yet show slightly at a different locationin the direction the carpet is being fed, and show up even more at stillother locations so that various shading effects may be created.Additionally, different effects may be created in cut and loop carpetsof the type manufactured using the method disclosed in U.S. Pat. No.3,084,645 and in level cut and loop carpet such as the type producedusing the method illustrated in U.S. Pat. No. 4,185,569.

When one considers that a full sized tufting machine such as a 4 meteror a 15 foot machine having a ⅛ gauge, i.e., ⅛ inch between rows ofneedles, may have as many as approximately 1298 needles such thatmulti-level single end control of the yam being fed would requireapproximately 1298 servo motors, it can be seen that there is a massivenumber of yarn ends being fed to the needles and that some means must befound to mount the motors and direct the yarns for threading the properneedle or the massive number of yarns would be intermingled orinterwinded and concatenated and make it extremely difficult forthreading the needles. If a particular yarn does not go to the properneedle, the pattern would be defective which may result in wastedfabric.

SUMMARY OF THE INVENTION

Consequently, it is a primary object of the present invention to providea yarn feed pattern assembly for a tufting machine that permits fullcontrol of the pattern repeat across the width of the tufting machinepermitting each needle to receive a respective yarn fed at amultiplicity of speeds selectively.

It is another object of the present invention to provide a yarn feedpattern assembly for a tufting machine having an individual motor driveassembly for each needle to permit feeding of the yarn at differentselective rates to each respective tive needle of the tufting machine.

It is a future object of the present invention to provide a yarn feedroller pattern assembly for attachment to a tufting machine, theassembly having an individual motor drive assembly for each needle andhaving a yarn guide system for guiding a yarn to and from eachrespective motor drive assembly.

Accordingly, the present invention provides a tufting machine having ayarn feed pattern assembly including a housing having a mounting platefor mounting a multiplicity of servo motors, each servo motor preferablycorresponding to one needle in the tufting machine so that a full repeatpattern across the width of the tufting machine may be provided. Eachservo motor carries a roller about which yarn is trained so as to be fedfrom a yarn source to the respective needle, the motor being mounted onone surface of the mounting plate and the roller being mounted on theother. Within the housing leading to and from each roller is arespective input and output tube, and the input tubes supplying yarnfrom the yarn source to the receptive roller and the output tubesfeeding yarn from the rollers to the respective needles. By maintainingthe yarn in the housing within the guide tubes, the yarn is precludedfrom being entangled with other yarns and provides the machine operatorwith the ability to thread each particular needle with the correct yarn.For example, any particular servo motor may carry a particular numberand the tubes extending thereto and therefrom may also be numbered tocorrespond with a particular needle. In this manner, the needles may bethreaded correctly to provide the desired pattern.

The housing which carries the servo motors and rollers and in which themultitude of yarn guide tubes are mounted may be readily mounted as anattachment, so to speak, on the head of the tufting machine and theyarns fed to the machine may be directed to the needles from the housingconventionally.

BRIEF DESCRIPTION OF THE DRAWINGS

The particular features and advantages of the invention as well as otherobjects will become apparent from the following description taken inconnection with the accompanying drawings in which:

FIG. 1 is a front elevational view of a tufting machine incorporating ayarn feed pattern attachment constructed in accordance with theprinciples of the present invention;

FIG. 2 is a fragmentary side elevational view of the machine illustratedin FIG. 1 with the end of the yarn feed pattern attachment housingremoved;

FIG. 3 is a perspective view of a portion of the mounting plate of theyarn feed pattern attachment broken away and rotated relative to FIG. 2to illustrate the servo motor and yarn drive associated therewith; and

FIG. 4 is a cross-sectional view taken substantially through line 4-4 ofFIG. 1 at a greatly enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, FIGS. 1 and 2 illustrate a tufting machine 10having a head 12 in which a plurality of transversely spaced push rods14 is reciprocally mounted, the push rods carrying a needle bar 16 atthe lower ends thereof. The needle bar 16 carries a multiplicity ofneedles 18, which may be mounted in a single roll as illustrated or intwo rows which may or may not be staggered relative to each other aswell known in the art. Moreover, rather than being a laterally fixneedle bar, the needle bar 16 may be of the laterally shiftable types asis well known in the art. In any event, the needles cooperate withcorresponding respective loopers and hooks (not illustrated)conventionally mounted beneath the head as is notoriously well known inthe art.

Mounted as an attachment on the head of the tufting machine is a yarnfeed roller pattern assembly 20 constructed in accordance with thepresent invention. Yarn, such as yarn strands Y, Y₁, Y₂, Y₃, Y₄, aresupplied from a source such as a yarn creel (not illustrated) and aredirected to the pattern attachment 20 and from the pattern attachmenteach yarn is directed to a respective separate needle 18.

The yarn feed roll pattern attachment 20 comprises a housing having afront face plate 22 spaced from a rear plate 24, the plates 22, 24 beingconnected together by end plates (not illustrated) so as to form ahollow housing having open upper and bottom portions. The rear plate 24may be connected to the tufting machine by means of brackets 26 so thatthe yarn is readily available for threading to the multiplicity ofneedles.

Secured to and carried by the front face plate 22 are a multiplicity ofyarn feed roll assemblies each including a respective servo motor 28,there preferably being one servo motor for each needle 18. As well knowneach servo motor may be controlled to rotate at variable selectedspeeds, and to this end electrical connectors 29,31 extend from themotors to a program controller (not illustrated). Each servo motor hasan outer casing 30 which is connected by screws 32 or the like to therear surface of the front face plate 22 while a yarn feed roller supportplate 34 is connected by screws 35 to the front surface of the plate 22in superposed relationship relatively to the servo motor. The outputshaft 36 of the each servo motor extends through the front plate 22 andthe support plate 34 and is connected to a roll 38, which, asillustrated, may have a pulley configuration. Thus the roller 38 mayhave a central circumferential recess within which a yarn may betrained. A lever yarm 42 has one end pivotally mounted on the plate 34and carries a disk or small roller 44 which is disposed to fit withinthe recess 40, a coil spring 46 connected at one end to the lever 42 andat it other end to a post 48 on the plate 34 acting to bias the leveltoward the roller 38 so that the disk 44 may place friction on the yamthat is within the recess 40.

Adjacent each plate 34 is a pair of apertures within which a receptivebushing 50, 52 is fastened. A first yam guide tube 54 preferablyconstructed from aluminum or plastic tubing is secured within eachbushing 50 and is bent to extend upwardly toward and preferably beyondthe top of the yarn fed roller assembly housing 20 while a similar tube56 is secured within each busing 52 and is bent to extend downwardly toadjacent the lower end of the housing 20. A yarn end may thus bethreaded into each tube 54 at the top, fed out the bushing 50, about thepulley 38, through the bushing 52, through the corresponding tube 56 andthereafter directed to the receptive needle 18.

Each servo motor is rotatably driven at a selected variable speed tofeed the respective yarn to the needle, the faster the motor is driven,the faster the roller 38 is rotated and the greater the amount of yarnfed to that needle. If the amount of yarn fed is less than the amountrequired by the needle system during its reciprocating path, then yarnis backrobvbed from the prior stitch to form a shorter loop in thatprior stitch. The various speeds that the servo motor may be drivenresults in variations in the pile heights in the various stitches sothat numerous patterns may be formed. Of course, as khown in the art,the control to the servo motors may be by means of a conventionalprogrammer or computer which is programmed with the desired pattern sothat on each stitch the required amount of yarn is fed to eachparticular needle. Accordingly, a full repeat or single end control maybe readily provided by the present invention in a simple manner.

Thus, the present invention provides a yarn feed roller assembly havinga housing wherein the servo motors may be mounted on a plate of thehousing and yarn guide tubes may be carried within the housing forguiding yarn to and from a yarn feed member driven by the servo motor.The yarn feed rolled assembly thus insures that the correct yarn is fedto and from each particular servo motor controlled yarn feed member.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to the preferred embodiment of theinvention which is for purposes of illustration only and not to beconstrued as a limitation of the invention. All such modifications whichdo not depart from the spirit of the invention are intended to beincluded within the scope of the appended claims.

1. A yarn feed roller assembly for a tufting machine comprising a hollowhousing having a mounting plate, a multiplicity of drive rollersrotatably mounted on said mounting plate, a multiplicity of variablespeed motors mounted on said mounting plate, each motor having an outputshaft connected to one of said rollers, and a multiplicity of yarn guidetubes mounted within said housing, there being two a first guide tubesassociated with each roller, one for directing yarn from a source to theroller and the other for directing yarn from the roller to the tuftingmachine , and a guide having an aperture through which said yarn isdirected from the roller to the tufting machine.
 2. A yarn feed rollerassembly as recited in claim 1, wherein said mounting plate comprises anexterior wall of said housing and includes an exterior surface and aninterior surface, said rollers extending from the exterior surface andsaid motors extending from said interior surface.
 3. A yarn feed rollerassembly as recited in claim 1, including a member for frictionallyengaging each roller to apply a frictional force to yarn trained aboutsaid roller.
 4. A yam feed roller assembly as recited in claim 1,wherein said tufting machine includes a head and brackets for attachingsaid housing to said head.
 5. A yarn feed roller assembly as recited inclaim 1 6, wherein said housing is open at an upper end and a lower end,said first guide tubes associated with said roller for directing yamfrom a source to the roller extend from said upper end and the secondguide tubes associated with each roller for directing yarn from therollers to the tufting machine extend to said lower end of said housing.6. The yarn feed roller assembly as recited in claim 1 wherein the guideroller comprises a second guide tube associated with each roller fordirecting yarn from the roller to the tufting machine.
 7. A yam feedroller assembly for a tufting machine comprising a hollow housing havinga mounting plate, a multiplicity of drive rollers rotatably mounted onsaid mounting plate, a multiplicity of variable speed motors mounted onsaid mounting plate, each motor having an output shaft connected to oneof said rollers, and a multiplicity of yarn guide tubes mounted withinsaid housing, there being a first guide tube associated with eachroller, for directing yarn from a source to the roller, said yarn thendirected from the roller to the tufting machine.